1. Field of the Invention
One embodiment of the present invention relates to a semiconductor device and an electronic device including a display device, or a driving method thereof.
Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. Furthermore, one embodiment of the present invention relates to a process, a machine, manufacture, or a composition of matter. Specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a lighting device, a power storage device, a memory device, a method for driving any of them, and a method for manufacturing any of them.
2. Description of the Related Art
An organic electroluminescent display device (hereinafter also referred to as OLED) is an example of a display device included in a semiconductor device. An image can be displayed on an OLED in such a manner that the gray level value of a display element in a display portion is controlled. Therefore, when the gray level of a video signal is higher, a higher-quality image can be obtained.
In order to increase the gray level of a video signal, a difference in potential supplied to a gate of a driving transistor should be small. In a source signal line driver circuit for driving a display device, a potential for displaying an image is selected from among a plurality of gray level power supply lines with the use of a D/A converter. In the case of a D/A converter using gray level power supply lines, the number of the gray level power supply lines needs to be the same as the obtained gray level; thus, the higher the gray level of a video signal is, the larger the number of the gray level power supply lines becomes (see FIG. 5A). As a result, the display device and the semiconductor device increase in size.
In recent years, the demand for higher image quality has been increased, and a semiconductor device with higher image quality, smaller size, and lower cost has been required.
Patent Document 1 discloses a structure in which two input potentials selected by a selection circuit are input to an amplifier circuit and a multilevel potential is output from the amplifier circuit.